How did Alexander the Great’s conquests alter the political landscape of the Afro-Eurasian world? What type of political regimes emerged in the wake of Alexander?

The biggest political change brought about by Alexander the Great's invasion is that it directly lead to the fall of Achaemenid Persia.After Alexander's death his empire splintered in to various kingdoms. These kingdoms were founded by Alexander's top ranking generals. Ptolemy I Soter founded the Ptolemaic Kingdom in Egypt, Palestine, and S.E. Anatolia. Seleucus I Nicator founded the Seleucid Empire centered in Mesopotamia and extended east to the Indus river was the largest of the successor kingdoms or diadochi. In Macedon Cassander, the son of Alexander's general Antipater, founded the Antipatrid Dynasty. These succesor states were frequently at war with one another over who would get total control over Alexander's vast Empire.